Mobiles typically incorporate a keypad, traditionally a particular and “physical” one of a very standardized layout, a 3×4 grid; but with the advent and swift acceptance of so called smartphones, now commonly integrated into sames' sole screen and thereon enacted by a user by light finger or “pen” touches.
This may be viewed as a disadvantage—by some missing the habitual tactility and acquired expertness at the physical keys and by some for its encroaching on the screen area—and visually impaired are disfavored; an active smartphone screen takes lot of battery etc.; and which all gives incentive for this invention.
While thus the sole functional visual user interface at common smartphones tends to be by some regarded as compromised or overcrowded by too many concurring elements, their backside remains virtually empty. Some ways of their assisting have been presented; for so called back-to-back displays in e.g. U.S. Pat. No. 7,768,605 for so called flip-up ‘feature’ phones (as contrasting to ‘smart’); and for smartphone types in US 2013/0222208 A1; this latter also discussing a back-to-back touch keypad (at paragraphs [0061-63], [0073], [0147], [0242-49]).
Existing solutions for mobile phones back-to-back displays/keypads are thus integrated into the phones and brand specific, which for users who just want such features occasionally and on their usual own smartphone may tend to be regarded as limiting and also expensive. Also, re keypads, they are so far not “physical” and as regards capacitive touch ones, they always need and consume much electric power for appearing/enactment, whereas physical keypads always are at hand (although switch-off-able) and just need negligible electric power for enactment.
To personalize and protect smartphones, a considerable market for and variety of so called cases/covers has emerged. The best reference to them that at the time of this application can be given is here thought to be at a site such as e.g. www.cellphoneshop.net/snapcover. It is there seen that being virtually identical, their main difference lies in which particular smartphone they are designed for, i.e. dimensional properties in order to fit and snap-on perfectly their host phone. Since even within same brand of smartphones measurements often change with new models, it is seen that a cover soon may become outdated and therefore should be kept quite cheap to facilitate change. From a technical point of view, though, they don't change. Their back, following and covering the smartphone's back, mostly just carries some decorative/ornamental art and is for the rest just a plastic sheet and can be varied in gauge and also hollowed without affecting the phone.